JP2011179453A - Rotary compressor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary compressor device that reliably reduces sliding loss generated on an eccentric part of a crankshaft and on an inner circumference of a roller, and has superior reliability and durability. <P>SOLUTION: The rotary compressor device is stored in a sealed container 1 where an electric motor 2 is connected to a compression mechanism 3 by the crankshaft 31. The compression mechanism 3 includes: a cylinder 30; a compression chamber 39 which is formed by an upper bearing 34 and a lower bearing 35 blocking both end faces of the cylinder 30; the roller 32 which is fitted to the eccentric part 31a of the crankshaft 31 installed in the cylinder 30; and a vane 33 which follows an eccentric rotation of the roller 32 and reciprocates in a slot provided in the cylinder 30, thereby separating the compression chamber 39 into a low and high pressure parts. In the device, a relief 42 is established on the eccentric part 31a in a tilting direction during an operation of the crankshaft 31. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotary compressor that can be incorporated into a refrigerator and an air conditioner.

  Conventionally, in a refrigeration apparatus, an air conditioner, and the like, a compressor that sucks gas refrigerant evaporated in an evaporator, compresses it to a pressure necessary for condensation, and sends high-temperature and high-pressure gas refrigerant into a refrigerant circuit is used. ing. A rotary compressor is known as one of such rotary compressors.

  A rotary compressor is generally an electric motor and a compression mechanism connected by a crankshaft and housed in a sealed container. The electric motor is formed by a rotor and a stator. A balance weight is provided in the vertical direction to reduce vibration and noise. The rotor is connected to the compression mechanism portion by a crankshaft, and the compression mechanism is operated by electrically rotating the rotor. At this time, since the rotor performs a rotational motion at the rotational speed specified in the operating conditions, a centrifugal force due to the rotation is generated. In addition, since the rotor is rotated by the electromagnetic force from the stator, a magnetic attraction force depending on the distribution of the gap between the rotor and the stator is also generated. The behavior of the crankshaft is determined by the influence of these external forces. The crankshaft is regulated in the rotational direction by the upper and lower bearings provided at the lower part of the rotor. The crankshaft and each bearing are provided with a certain gap to prevent direct contact as much as possible. The crankshaft is held by this.

  The compression mechanism is fitted to a compression chamber formed by a cylinder, an upper bearing and a lower bearing that close both ends of the cylinder, and an eccentric portion of a crankshaft supported by the upper bearing and the lower bearing in the compression chamber. And a vane that abuts the outer periphery of the roller and reciprocates following the eccentric rotation of the roller to partition the compression chamber into a low pressure portion and a high pressure portion. The cylinder is provided with a suction port for sucking gas toward the low pressure part in the compression chamber, and the upper bearing is provided with a discharge port for discharging gas from the high pressure part formed by turning from the low pressure part in the compression chamber. The roller is accommodated in a compression chamber formed by a cylinder closed from above and below by an upper bearing and a lower bearing. The discharge port is formed as a circular hole passing through the upper bearing in a plan view, and a discharge valve is provided on the upper surface of the discharge port that is released when a pressure of a predetermined magnitude or more is applied.

  In the rotary compressor configured as described above, on the low pressure part side, the sliding contact part of the roller passes through the suction port and moves away from the suction chamber while gradually expanding, and sucks gas from the suction port into the suction chamber. On the other hand, on the high pressure part side, the sliding part of the roller approaches the discharge port while gradually reducing the compression chamber, and when the pressure is compressed to a predetermined pressure or higher, the discharge valve opens and gas flows out from the discharge port.

  In such a rolling piston type fluid machine, the roller is pressed against the eccentric portion of the crankshaft due to the pressure difference between the high pressure portion and the low pressure portion, and the crankshaft is tilted by the pressing force. Further, the crankshaft is tilted by the above-described external force such as the centrifugal force and magnetic attractive force of the rotor. When the crankshaft is tilted, the eccentric portion of the crankshaft and the inner circumference of the roller or the lower bearing are brought into contact with each other, thereby generating a loss.

FIG. 11 shows a conventional rotary compressor described in Patent Document 1. In FIG. As shown in FIG. 11, sliding loss is reduced by forming a barrel shape in which the diameter of the central portion of the eccentric portion 31a of the crankshaft 31 is slightly larger than the diameter of the end portion (see, for example, Patent Document 1). )
.

Japanese Utility Model Publication No. 63-136285

  In a conventional rotary compressor, if the crankshaft is tilted, the eccentric part of the crankshaft and the inner circumference of the roller or the lower bearing come into contact with each other, which not only increases sliding loss but also causes abnormal wear. , Reliability and durability may be impaired. Further, if the crankshaft is provided with a relief without considering the direction of inclination, the bearing gap becomes too large depending on the direction of inclination, which has the problem of further reducing the reliability of the bearing.

  The present invention solves the conventional problems of the previous term, and reliably reduces the sliding loss generated in the eccentric part of the crankshaft and the inner circumference of the roller or the lower bearing, and is excellent in reliability and durability. The purpose is to provide.

  In order to solve the above-described conventional problems, the rotary compressor according to the present invention is characterized in that the crankshaft rotates while the crankshaft is inclined, and a relief corresponding to the inclination direction is provided in the eccentric portion of the crankshaft. It is what. As a result, by providing a relief corresponding to the direction in which the crankshaft tilts, contact between the eccentric part of the crankshaft and the roller inner periphery or the lower bearing is avoided, and sliding loss is reliably reduced, reliability and durability. It becomes a rotary compressor excellent in performance.

  In the rotary compressor of the present invention, by providing a relief corresponding to the inclination generated in the crankshaft in the eccentric part of the crankshaft, it is possible to suppress a decrease in reliability and durability such as wear and seizure, and an appropriate amount. Since the bearing surface can be secured, the sliding loss can be surely reduced, so that a highly reliable and highly efficient rotary compressor can be provided.

The longitudinal cross-sectional view of the rotary compressor in Embodiment 1 of this invention The schematic diagram of the eccentric part of the roller and crankshaft in Embodiment 1 of this invention The characteristic view which shows the relationship between the magnetic attraction force and clearance gap distance in Embodiment 1 of this invention The schematic diagram of the eccentric part of the roller and crankshaft in the general shape in Embodiment 1 of this invention The characteristic view which shows the locus | trajectory at the time of the driving | running | working of the crankshaft in the general shape in Embodiment 1 of this invention. The characteristic view which shows the relationship of the clearance gap at the time of the assembly in Embodiment 1 of this invention The schematic diagram which showed the installation angle of the escape in Embodiment 1 of this invention The schematic diagram which showed the shape of the escape in Embodiment 1 of this invention The schematic diagram which showed relief of the thrust surface in Embodiment 1 of this invention Sectional drawing which shows the shape of the eccentric part of the crankshaft in Non-Patent Document 1 of the conventional example

According to a first aspect of the present invention, an electric motor and a compression mechanism are connected by a crankshaft and housed in a sealed container. The compression mechanism includes a cylinder, an upper bearing that closes both end surfaces of the cylinder, and a lower bearing. A compression chamber formed by a bearing, a roller fitted in an eccentric portion of the crankshaft provided in the cylinder, and a reciprocating motion in a slot provided in the cylinder following the eccentric rotation of the roller In the rotary compressor comprising a vane that divides the compression chamber into a low pressure part and a high pressure part, the eccentric part is provided with a relief in the tilting direction during the crankshaft operation. Even if the crankshaft is inclined, contact between the crankshaft eccentric portion and the inner circumference of the roller is avoided, so that a highly reliable and highly efficient rotary compressor can be provided.

  The second aspect of the invention is particularly based on the eccentric direction of the crankshaft of the first aspect of the invention. The rotational direction of the outer periphery of the eccentric part is -30 degrees to 150 degrees, and the upper bearing side is escaped. By providing a relief on the lower bearing side, an optimum relief shape that matches the tilting direction of the crankshaft is obtained, and high reliability and high efficiency can be reliably achieved.

  According to a third aspect of the present invention, in particular, the escape shape of the eccentric portion of the first or second aspect is a taper shape having a continuous inclination, so that the one-piece contact with respect to the inclination of the crankshaft. Can be secured, the oil film surface can be secured, and a high oil film holding power can be maintained.

  The fourth aspect of the invention is particularly characterized in that the shape of the eccentric part of the first or second aspect of the invention is a shape that draws a smooth curve such as a circular arc in which the eccentric part is continuous. Point contact, the contact area can be suppressed, and the loss generated can be reduced.

  The fifth aspect of the invention is particularly characterized in that the thrust surface provided on the lower bearing side of the eccentric part of any one of the first to fourth aspects of the invention is provided with a relief in the tilting direction during the crankshaft operation. As a result, even if the crankshaft is inclined by an external force, contact between the crankshaft eccentric portion thrust surface and the lower bearing end surface is avoided, so that a highly reliable and highly efficient rotary compressor can be provided.

  In a sixth aspect of the invention, in particular, the thrust surface provided on the lower bearing side of the eccentric portion according to any one of the first to fifth aspects of the invention is arranged in the rotational direction with reference to the eccentric direction of the crankshaft. 30 to 150 degrees is characterized by having a lower vertical height than 150 to 30 degrees, making it an optimal relief shape that matches the tilt direction of the crankshaft, ensuring high reliability and high efficiency Can be achieved.

  The seventh aspect of the invention is particularly characterized in that the relief shape of the thrust surface provided on the lower bearing side of the eccentric part according to any one of the first to sixth aspects is a tapered shape having a continuous inclination. By doing so, it is possible to prevent the crankshaft from tilting against each other, to secure the oil film surface, and to maintain a high oil film holding force.

The eighth invention is characterized in that, in particular, CO ₂ that is a high-pressure refrigerant is used as the working fluid according to any one of the first to eighth inventions, so that the differential pressure is particularly large and the crankshaft is greatly inclined. Thus, it is possible to provide a highly reliable and highly efficient rotary compressor more effectively with CO ₂ .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a longitudinal sectional view of a hermetic compressor according to a first embodiment of the present invention. In FIG. 1, the rotary compressor is a motor in which an electric motor 2 and a compression mechanism 3 are connected by a crankshaft 31 and housed in a sealed container 1, and the compression mechanism 3 includes a cylinder 30 and both end faces of the cylinder 30. A compression chamber 39 formed by an upper bearing 34 and a lower bearing 35 for closing the roller, and a roller fitted in the eccentric portion 31a of the crankshaft 31 supported by the upper bearing 34 and the lower bearing 35 in the compression chamber 39. 3
2 and a vane 33 that reciprocates following the eccentric rotation of the roller 32 while abutting on the outer periphery 32a of the roller 32 and partitions the inside of the compression chamber 39 into a low pressure portion and a high pressure portion. The cylinder 30 is opened with a suction port 40 for sucking gas toward the low pressure portion in the compression chamber 39, and the upper bearing 34 receives gas from the high pressure portion formed by turning from the low pressure portion in the compression chamber 39. A discharge port 38 for discharging is opened, and the roller 32 is accommodated in a compression chamber 39 formed by the cylinder 30 being closed from above and below by an upper bearing 34 and a lower bearing 35.

  The discharge port 38 is formed as a circular hole passing through the upper bearing 34 in plan view, and a discharge valve 36 is provided on the upper surface of the discharge port 38 that is released when a pressure of a predetermined size or more is applied. And a cup muffler 37 that covers the discharge valve 36. On the low pressure portion side, the sliding contact portion of the roller 32 passes through the suction port 40 and gradually moves away from the suction chamber, and sucks gas from the suction port 40 into the suction chamber. On the other hand, on the high pressure portion side, the sliding portion of the roller 32 approaches the discharge port 38 while gradually reducing the compression chamber 39, and when the pressure is compressed to a predetermined pressure or higher, the discharge valve 36 opens and the gas is discharged from the discharge port 38. And is discharged into the sealed container 1 from the cup muffler 37, passes through the notch 28 formed by the stator 22 and the inner wall of the sealed container 1, and the air gap 26 of the motor 2, and the upper shell of the upper part of the motor 2. 5 and is discharged from the refrigerant discharge pipe 51 to the outside of the sealed container 1. Arrows indicate the refrigerant flow.

  About the rotary compressor comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. FIG. 2 is a schematic diagram of the eccentric portion 31 and the roller 32 of the crankshaft 31 according to the present invention. As shown in FIG. 2, a relief 42 is provided in the eccentric part 31 a of the crankshaft 31 in the direction of tilting the crankshaft. In the present invention, the relief 42 refers to a shape in which the maximum diameter 31 b of the portion where the relief 42 is provided is smaller than the maximum diameter 31 c of the eccentric portion 31 a of the crankshaft 31.

  In general, the shape of the eccentric portion 31a of the crankshaft 31 on the inner periphery 32b side of the roller 32 is designed so as not to be inclined in the vertical direction. This is because the crankshaft 31 has a high reliability and a low loss shape if the crankshaft 31 is not tilted and maintains a vertical state and rotates. However, during actual operation of the rotary compressor, the crankshaft 31 is tilted by an external force such as a pressing force due to the high / low pressure difference of the compression chamber 39, a centrifugal force of the rotor 24, and a magnetic attractive force. The centrifugal force of the rotor 24 shown here is a force generated in the rotor 24 including elements such as the balance weight 41 attached to the rotor 24. The magnetic attraction force shown here is a force generated by the gap between the rotor 24 and the stator 22 due to the characteristics of the electric motor 2 as represented by FIG. When these external forces act and the crankshaft 31 tilts, the outer periphery 31d of the eccentric portion 31a of the crankshaft 31 and the inner periphery 32b of the roller 32 make abnormal contact as shown in FIG. Loss. At this time, according to the configuration of the present invention, by providing a relief corresponding to the inclination of the crankshaft 31 in the eccentric portion 31a of the crankshaft 31, avoiding a single contact with the inner periphery 32b of the roller 32, and reducing the loss. Can do.

  In addition, although the inclination direction of the crankshaft 31 is affected by the above-described external force or the like, in a general rotary compressor, cranking is performed under operating conditions in which the sliding state is severe among typical air conditioner performance evaluation conditions (APF conditions). When the tilt direction of the shaft 31 is measured, as shown in FIG. 5, the tilt occurs most when the rotation angle of the crank shaft 31 is around 210 degrees, and the tilt direction rotates when the position of the vane 33 is used as a reference. Tilt in the direction of about 270 degrees.

This also coincides with the calculation result in consideration of the pressing force due to the high / low pressure difference, the elastic deformation of the crankshaft 31, the centrifugal force of the rotor 24 including the balance weight 41, and the magnetic attraction force against the rotor 24. In this calculation, the pressing force is obtained from the torque fluctuation due to the pressure difference generated by changing the volume of the compression chamber 39 by the rotation of the rotary compressor as shown in FIG. The elastic deformation δ [mm] of the crankshaft 31 is the following equation: δ = Pl / kEI (where P: load applied to the shaft [N], l: shaft length [mm], E: longitudinal elastic modulus [MPa] , I: sectional moment of inertia [
mm ⁴ ], k: a constant that varies depending on the shaft support method), and the amount of deflection of the crankshaft 31 is obtained by the force applied by torque fluctuation. The magnetic attraction force is obtained from the characteristic of the electric motor 2 as shown in FIG. 3 and from the distance that changes due to the bending of the crankshaft 31 or the like. For the centrifugal force, a generally used formula of F = mrω ² is applied. At this time, F is the centrifugal force, m is the mass of the entire crankshaft 31, and ω is the rotational speed of the crankshaft 31. The trajectory of the crankshaft 31 is calculated from these formulas.

  From these facts, as shown in FIG. 7, the optimum range for the inclination of the crankshaft 31 is that when the rotation angle of the crankshaft 31 is 210 degrees, the inclination direction is the rotation when the position of the vane 33 is used as a reference. If it is inclined most in the direction of 270 degrees in the direction, the outer bearing 31d of the eccentric portion 31a is centered on the position of 60 degrees in the rotational direction with respect to the eccentric direction of the crankshaft 31, and the upper bearing 34 is in the range of -30 degrees to 150 degrees By providing a relief on the side, centering on 240 degrees, and providing a relief on the lower bearing 35 side from 150 degrees to 30 degrees, high reliability and high efficiency can be reliably achieved. The set angle at this time can be changed according to the conditions in various rotary fluid machines by the above-described calculation formula. In the present embodiment, the above formula is used, but the present invention is not limited to this.

  In addition, the shape of the above-described relief 42 can be a simple shape and can be formed by providing a step in the range of the relief 42. However, by forming a tapered shape with a continuous slope as shown in FIG. It is possible to prevent contact with respect to the inclination of the shaft 31, secure an oil film surface, and maintain a high oil film holding force.

  Further, as shown in FIG. 8, by attaching R having an outer shape smaller than the width of the relief 42 to the surface of the above-described relief 42, the oil film holding force is insufficient due to a sudden load fluctuation or the like, and the eccentric portion 31 a of the crankshaft 31. Even if contact between the outer periphery 31d of the roller and the inner periphery 32b of the roller 32 occurs, the shape of the relief 42 of the eccentric portion 31a of the crankshaft 31 is a shape that draws a smooth curve such as a continuous arc. As a result, point contact is achieved, the contact area can be suppressed, and the loss generated can be reduced. Here, the width of the relief 42 is a difference in diameter between the relief side and the opposite side.

  Further, as shown in FIG. 9, the thrust surface 43 provided on the lower bearing 35 side of the eccentric portion 31 a of the general crankshaft 31 is designed to form a horizontal surface with respect to the vertical direction of the crankshaft 31. The This is also the same as the shape of the eccentric portion 31a on the inner periphery 32b side of the roller 32. The crankshaft 31 is not inclined, and no problem occurs when the crankshaft 31 is rotated. However, the crankshaft 31 is inclined. In this case, a piece is generated and a loss occurs. In order to avoid contact between the thrust surface 43 of the eccentric portion 31a of the crankshaft 31 and the end surface of the lower bearing 35 by providing a relief 42 corresponding to the inclination on the thrust surface 43 of the eccentric portion 31a of the crankshaft 31 at this time. A highly reliable and highly efficient rotary compressor can be provided.

  Needless to say, the same effect can be obtained by setting the setting range of the relief 42 and the shape of the relief 42 in the same manner as the eccentric portion 31a of the crankshaft 31 described above. Furthermore, it goes without saying that the same effect can be obtained even if the same relief 42 as described above is formed on the upper bearing 34 side.

Further, by using CO ₂ which is a high-pressure refrigerant as the working fluid, it is more effective, more reliable and more efficient especially in CO ₂ where the differential pressure is large and the inclination of the crankshaft 31 is large. A rotary compressor can be provided.

In the present embodiment, the eccentric portion 31 a of the crankshaft 31, the eccentric portion 31 a of the crankshaft 31, and the thrust surface 43 are provided with relief, so that in the conventional structure, the eccentricity of the crankshaft 31 is caused by the tilting of the crankshaft 31. The contact between the outer periphery 31d of the portion 31a and the inner periphery 32b of the roller 32 occurs, and the tilt of the roller 32 can be suppressed, and the occurrence of contact between both ends of the roller 32 in the vertical direction can be suppressed, and the sliding loss can be reduced. Reduction can also be achieved.

  In addition, since the inclination of the roller 32 can be reduced in the present embodiment, the gap setting between the roller 32 and the inner periphery 30a of the cylinder 30 at the time of assembly can be made narrower than the conventional gap. The leakage loss of the fluid from the gap | interval of the periphery 30a can be suppressed.

As described above, the rotary compressor according to the present invention can suppress deterioration of reliability such as wear and seizure, and simultaneously reduce leakage loss and sliding loss, thereby improving the efficiency of the compressor. It becomes. Thereby, in addition to the compressor for an air conditioner using an HFC refrigerant or an HCFC refrigerant, the present invention can be applied to uses such as an air conditioner using a natural refrigerant CO ₂ and a heat pump type hot water heater.

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Electric motor 3 Compression mechanism part 30 Cylinder 31 Crankshaft 31a Eccentric part 31d Eccentric part outer periphery 32 Roller 33 Vane 34 Upper bearing 35 Lower bearing 39 Compression chamber 42 Relief 43 Thrust surface

Claims (8)

An electric motor and a compression mechanism portion are connected by a crankshaft and housed in a sealed container, and the compression mechanism portion is formed of a cylinder, and an upper bearing and a lower bearing that close both end surfaces of the cylinder. A compression chamber, a roller fitted in an eccentric portion of the crankshaft provided in the cylinder, and a reciprocating motion in a slot provided in the cylinder following the eccentric rotation of the roller to move the compression chamber The rotary compressor which consists of a vane partitioned into a low-pressure part and a high-pressure part, wherein the eccentric part is provided with a relief in the tilting direction during the crankshaft operation. Based on the eccentric direction of the crankshaft, the upper bearing side is released from -30 to 150 degrees in the rotational direction of the outer periphery of the eccentric part, and the relief is provided on the lower bearing side from 150 to 30 degrees. The rotary compressor according to claim 1, wherein The rotary compressor according to claim 1 or 2, wherein the relief shape of the eccentric portion is a tapered shape having a continuous inclination. The rotary compressor according to claim 1 or 2, wherein the eccentric portion has a shape that draws a smooth curve such as an arc having a continuous relief shape. The rotary compressor according to any one of claims 1 to 4, wherein a thrust surface provided on the lower bearing side of the eccentric portion is provided with a relief in a tilting direction during the crankshaft operation. Based on the eccentric direction of the crankshaft of the thrust surface provided on the lower bearing side of the eccentric part, the vertical direction has a lower height of −30 ° to 150 ° than 150 ° to 30 °. The rotary compressor according to claim 1, wherein the rotary compressor is provided. The rotary compressor according to any one of claims 1 to 6, wherein a relief shape of the thrust surface provided on the lower bearing side of the eccentric portion is a tapered shape having a continuous inclination. Rotary compressor of any one of claims 1 to 7, characterized by using the CO ₂ is high-pressure refrigerant as a working fluid.